In many medical disciplines, thin and elongated carrier tubes carrying imaging devices are inserted into a patient's body to inspect areas of interest of the body for diagnostic purposes, or to aid medical personnel in chirurgical procedures. In the insertion and motion of the carrier within the body lumen, a control technique should be provided to ensure that the image capturing device's field of view (FOV) includes the region of interest, and does not veer from away from a desired orientation.
For example, in colonoscopy, an examination of body lumens, such as the colon and part of the small bowel, is performed with a CCD camera or a fiber optic camera on a flexible carrier passed through the anus. The examination may provide a visual diagnosis (e.g. ulceration, polyps) and grant the opportunity for biopsy or removal of suspected lesions. In colonoscopy, during at least a preliminary inspection sweep (i.e. a passage of the carrier throughout the length of a chosen lumen), the camera should be kept near the central axis of the inspected lumen and pointing forward. In this manner, the area of lumen walls in the camera's FOV is maximized, thereby increasing the accuracy of the inspection. The inspection time is also reduced, thereby reducing the patient's discomfort.